


Blue Moon

by otterbeans



Category: Shingeki no Kyojin | Attack on Titan
Genre: 5000 words is too long for pwp, Multi, Other, Threesome - F/M/M
Language: English
Status: Completed
Published: 2014-03-17
Updated: 2014-03-17
Packaged: 2018-01-16 03:20:40
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 5,182
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/1329991
Author URL: https://archiveofourown.org/users/otterbeans/pseuds/otterbeans
Summary: <blockquote class="userstuff">
              <p>It's not often that the three of them are able to meet like this.</p>
            </blockquote>





	Blue Moon

**Author's Note:**

> This has been stewing in my documents for more than half a year. Threesomes are impossible. Please make it stop. I can't take anymore.
> 
> Enjoy.

The three of them ending up together happens about as often as the moon turning twice in one month. It's only the nature of the thing; being in the same division doesn't guarantee closeness, in fact they have long since been partitioned into their separate roles.

The strategist works closely with the commander and very rarely leaves his side. The squad leader has responsibilities to her crew as well as humanity as the most skilled Titan slayer in the Corps. And the lynchpin lives in shadows, moving from place to place without word of his departure or arrival. Information of his whereabouts is too sensitive; every person that knows his location is another possible threat. His continued survival must be ensured at all costs.

They say that when you carry someone in your heart, you'll always know where they are. That isn't true. However, it does make you that much more likely to hear their name when mentioned in whispers. It's a combination of serendipity and diligence when one of them follows the trail from one mouth, to another, to another, eventually ending in a pleasant reunion.

However, it is usually one, or the other. And that's okay. They're never disappointed in seeing someone that they miss. Talk always gravitates towards whoever isn't there, as if honoring their memory, but it doesn't stop them from seeking comfort in each other in the end.

The day is a grey, where the sun tries and cannot break through the high and unthreatening clouds. Armin follows the motes of dust floating up in the fragile light as the old books and maps are disturbed, peering out at the yard through the window from the corner of his eye. The squads are preparing the horses and wagons. The sound and smell is familiar, although he has not been directly responsible for such proceedings in some time.

Mikasa is out there with her squad. She has an intimidating reputation, but that's only to be expected. Mikasa could intimidate grown men since she was ten. What does not come as naturally to her in leading a squad was handling her charges as humans and gaining true respect. It doesn't help that the entirety of the Corps is getting younger and younger, and she was promoted just as young. But they're adapting, and more encouragingly, improving.

The intelligence isn't official, but Eren is out there somewhere. They will need him for their first push towards eastern territory and as a failsafe in case shifters decide to harry them. Although he technically holds no title and has no troops, their own shifters have a habit of taking orders from him before listening to command. A bad habit. It seems as long as he will live, humanity will continue to be forced to rely on him. It's good fortune it is a burden he is willing to bear, if he is somewhat ill-suited to telling anyone what to do. The power fell on him unbidden.

Preparations continue well into the night. The soldiers set up camp and take shifts sleeping. Armin is studying the same map and mission briefings again and again, by a candle that's turned into a pool of wax with a wick and has killed about a dozen moths in its molten depths. He's about to nod off into his desk when a knock makes him jump.

"Specialist Arlert?"

A young voice calls, muffled. Armin is used to people just walking in. He's never made pretenses about his position. Just hearing the word "specialist" causes him chagrin.

He dusts himself off and takes off his glasses to rub at the tired eyes beneath them.

"Yes? Come in."

A young man with a freshly tailored Recon Corps mantle opens the door. He holds the rim of his hood close to his head, and in the shadows it's hard to make out the details of his face.

"I-- I was told that you should follow me, sir," the boy says, with thinly veiled apprehension.

"By whom?"

It's here that he begins to stumble.

"Well you see, sir, I can't really," he gulps, "I would tell you if I could, but I honestly don't know myself. Or rather, I'm not supposed to know. You're not supposed to know. Nobody is--"

"--supposed to know," Armin finishes his sentence, and rises from his seat, "I think I understand. Can you take me where ever it is I'm to go?"

The boy sighs in relief and nods, holding the door open for his superior. He then takes him through the inner corridors of the hold, which Armin knows about, and then down a hatch hidden under a pallet of supplies, which Armin most definitely does not know about.

Apparently being a lead strategist doesn't afford you full knowledge of every keep and castle in the border towns. There must always be a place where one can potentially stay hidden from every possible set of eyes.

"There's only one way down this hall, so," the young man steps back, and salutes, "with your permission, sir."

"Yes," Armin feels half inclined to salute in return. He would never get used having a rank, "you're relieved of your duty, soldier. Thank you."

He nods and scurries off with nary another word or backwards glance. Under his hood, he smiles. It's not every day a rookie like him gets to meet a living legend...

The hall is dark, but dry. A few torches glow in iron braziers and flicker dancing lights across the walls. Armin's boots echo loudly on the stone floors as he passes two Corps guards standing at a turn in the tunnel.

They barely bat an eyelash at him. He recognizes their faces, and nods to them in appreciation.

At the end of the corridor is a heavy, old oaken door. The kind designed to lock people away. Even now, these were the kinds of places he ended up in.

"Armin," he says, with an eager smile.

"Eren," Armin replies, a similar fondness in his lips.

How long had it been? Weeks? Months? Out of them all, he had to be the most difficult to track down, and so Armin saw him the least. But there was a strange sort of immortality to Eren, stubborn and unchanging. It was as if he had just seen him yesterday.

Eren is in plain clothes, sitting on a hastily made mattress of some soft material for his immediate comfort. His uniform and gear sit neatly arranged in an opposite corner. He once had a captain that wouldn't abide anything less.

"Come here," he beckons with a welcoming gesture, "take a load off."

Armin nods, sits down next to him, and shrugs off his jacket. As he leans over to undo his boots, he feels Eren starting to loosen and unbuckle his belts where he can.

Removing everything doesn't take nearly as long as it does to put it on, but it's a process.

"Sorry about the kid," Eren apologizes as they both slowly pull apart the harness, "I can't even fart without leave right now. And I only have those two guards..."

He huffs, because it's absurd. Like two guards could hold him anywhere. And since they're the only ones, there isn't anyone available to do him even the smallest of favors.

Armin only chuckles.

"Little good penning you up here is going to do. That boy recognized you. He's going to tell his entire squad as soon as he gets the chance."

"What? Dammit. I thought if I picked a younger one, they wouldn't know..."

With a final click, the last of Armin's harness falls to the ground in a complicated jangle. He absently itches in relief through his clothes at the permanent calluses formed where the straps chaffed his skin. Taking off one's uniform was one of life's true joys.

"Eren, we're not cadets anymore," he chides gently; "It's been five years. He was old enough to have seen you returning from a mission as a child before enlisting in the military. Do you ever take that into account?"

"I would have just been a green brat then though," Eren replies, worrying his hands in a way that tell that he does think about it. About being dragged back from the front lines in various states of mangled unconsciousness, "nothing worth idolizing. No way."

"Alright then. Give it awhile longer," Armin says, and places a hand over Eren's, "Until then, remember that you certainly have starry-eyed children looking up to you now, and you should probably start acting like it."

"...I'm not that bad."

He chuckles, and pats Eren's shoulder.

"Would you rather not speak of such things?"

"Nah," Eren replies, and wraps his arms around Armin's waist. Armin leans his head against Eren's in return, "Not many people scold me anymore. It's kinda refreshing to hear you say stuff like that."

"I wouldn't call it scolding..."

The door creaks, and the two come to attention immediately. Eren smiles and gets up, ready to greet his guest with open arms. It could only be one person.

"Mikasa," he says, and embraces her. She does not squeak, or gasp in surprise, but holds him in return with as much quiet passion.

There was a time when she was taller than him, but that has long since passed. Now their heights are just perfect for her to nuzzle her face in his collar and murmur his name in return.

Left undisturbed, she was the type that could linger in this position for a long time. They let her. Eren rubs her back. Armin arranges the pillows and blankets on the pallet to be more comfortable. She only pulls away when the knowledge that their time is precious motivates her enough to move.

Mikasa walks over to the bed, and lightly holds Armin's chin to angle his head so she may kiss him on the temple. He smiles and reaches up to stroke her thick, black hair.

"I was wondering when you would manage to get here," he says, as she sits down, "all three of us present at the same time-- it's practically a miracle."

"Yes, it is," she replies, "however, I was given directions to this cellar by one of my own new recruits..."

"Fuck, really?"

Armin chokes in an attempt not to laugh, as Eren gapes in dismay. Mikasa raises an eyebrow.

"So you spoke to him directly?"

"Yeah, but-- I mean, come on, what are the chances? I thought your squad was only supposed to have elite members? The kid was so green!"

"Yes, he tends to be nervous," she sighs. "But he graduated with top marks... I have high hopes for his survivability."

There's a second's silence as she thinks something over while removing her jacket.

"...However, he seemed excited about his squad leader meeting in secret with The Titan-Caller Yeager. His apprehension about tomorrow's mission was gone. It was a side of him I haven't seen yet."

She heaves a sigh.

"He'd be disappointed if he knew what we were actually doing."

By now, Armin is really trying hard not to break into some very ugly laughter.

"C-come now," he coughs out between barely-contained snickers, as Eren is too mortified to speak, "let's not ruin the boy's perception of the Corps with less savory realities straight away. Let him think all he wants of secret proceedings in dark basements. It's not his time yet."

"I don't think it's my time yet," Eren shivers, thinking about all the times he'd been conveniently sent away, or given a private message while under someone else's command. He knows exactly what he's doing, but he doesn't want to know exactly what his _superiors_ are doing.

Mikasa is always impervious to such embarrassing talk. She's trying to take off her harness.

"Could you help me with this?"

'You' being either one of them, with her back turned in their general direction. Eren reaches out to undo the plates at the small of her back, where the maneuver gears engine would normally attach. She's already gotten all of the belts on her upper-body off, so she starts to unbutton her shirt as well.

"Ah, Mikasa," Armin murmurs.

Removing her shirt revealed the marks her harness left on her body. Since she sees so much more action that he does, her calluses ware harder, her bruises angrier, and her blisters more painful. Armin will always have marks here and there, but for Mikasa, it's as if someone has printed the straps of her belts onto her skin.

Eren, who has none whether he uses his gear or not, can only look on with vaguely remembered sense of empathy.

"Having you been drilling a lot recently?" Armin asks, as he gently traces the worst of her wounds with the lightest of touches, "some of these have been aggravated. Eren, do you-- no, of course you don't. Er..."

"I have some," Mikasa cuts in quietly, and retrieves a small tin with a clasping lid from the pocket of the jacket she had discarded on the bed.

Inside is a medicinal salve commonly used by all soldiers to treat and sooth minor wounds, especially chaffing caused by the harnesses they all wore. Someone always seems to have some on hand when you need it.

"Good, good. You'll have some on your legs too, right? I can take care of that, so..."

Take off your pants. Those are words he refuses to say, ever. She's already willingly sitting there in naught but her bindings, and he's seen her completely naked enough times to recall her form by memory, but there are some places Armin just won't go.

Mikasa understands, although his approach doesn't particularly concern her. She nods and shimmies out of her trousers. As Armin expected, there are more abrasions around her thighs and calves.

"This might take awhile," he mutters, and she shrugs, leaning comfortably against Eren. He kisses her on the forehead as silent apology as Armin slowly and carefully treats each of her blisters.

The salve stings at first, but cools down after it is applied. Mikasa bears it well. Armin notes how her skin can be so soft in some places, yet hard and scaled in others. He holds her thigh loosely up in his hands and runs them down to her foot, purely for his own pleasure, feeling the changes in texture from her calluses under his fingertips. Even with her battle-hardened physique, her legs have a slight, fleshy give.

She raises an eyebrow at him, and he smiles and shakes his head, going back to applying the ointment the last of her sores.

"There," he says, and wipes the last of the residue on his fingers off on the sheets, "done. I wish we had bandaging, but this will do for now."

"Thank you," Mikasa replies, reaching out to stroke his cheek. Armin never did manage a beard. She traces her fingers upwards, and removes his glasses in one deft motion.

"I always forget how damn blue your eyes are," Eren adds with a grin.

"My eyes? You're the one with such a freakish shade of-- ow ow ow!"

As Armin starts to complain, Eren quickly tugs his hair band out, undoing his ponytail. His cornsilk hair falls out slightly wavy from being held up for so long.

"Warn me when you do that!" he groans, eyes watering.

"Look," Eren grins, and nudges Mikasa resting in the crook of his arm, "it's longer than yours now."

"I just had it cut," Mikasa says offhandedly, touching at the black hair bobbed just barely under her ears, "I don’t like hair bands. They're uncomfortable."

"I like them just fine," Armin protests, resisting the urge to scratch at his scalp or rearrange his locks, "they keep things out of the way-- which won't be happening now."

"You look too official with it up," Eren shrugs, and reaches with his free hand to touch that soft hair, "this is how I remember you."

Armin can't argue with that. He sighs, and holds Eren's hand.

"...I never cut it short for a reason."

Eren smiles, because he knows. Just one thing in a sea of uncertainty is worth some happiness. He leans forward to give Armin a proper kiss.

When they break away, a glance of eye-contact is enough to convey their intent. Armin beings to unbutton his shirt while Eren is already his pulling his over his head. Mikasa undoes the bindings that hold down her breasts, which distracts them both for a long-suffering moment.

(She doesn't mind.)

Eren has the less complicated shirt and therefore gets first dibs on a chest-to-chest hug with her, but she obliges Armin without asking as soon as he finishes with his.

Skin contact is so blessed when you wear a uniform 24/7 that literally straps you in. That warm, distinctly soft sensation almost becomes surprising after long enough. Armin lies back with Mikasa still on top of him, savoring the feeling, but Eren won't take being left out for long, and pulls the both of them towards him, one on each side. Mikasa cuddles tightly against him, and Armin rests his head on his shoulder.

Sounds of contented breathing permeate the room. Eren's skin is always slightly warmer than expected.

"...Too much of this, and I'm likely to fall asleep," Armin murmurs.

The others make noises that are somewhat laughing, but also belying their agreement. Eren sits up, bringing the two up with him.

"It's all those books," he says, "they'll make your eyes fall out of your skull."

"Mm. Come here," Mikasa beckons, taking Armin's face in both hands.

_We only have so much time._

Mikasa kisses him, leaning her chin up and leaning his chin down. He plays with her breasts, feeling their heavy and warm weight under his palms. She rests her back square against Eren's chest, sitting in his lap, and he leans back to give them space as they kiss, sneaking his fingers down her taut abdomen and into her underwear. Her cleft is already quite wet.

As much as both of them would like to have real, penetrative intercourse with her, they would also have to be completely insane to go through with it. Pregnancy would make Mikasa temporarily useless at least and could kill her at worst, and if it happened, their heads would be the first on the chopping block for destroying one of humanity's best chances for revival.

Besides, just ask anyone in the Military. They'll give you their own tips for getting around it.

After fingering Mikasa long enough to spread around her wetness and feel her clit peak, Eren shimmies off her underwear the rest of the way with her own eager help. Armin gives her one last lingering kiss and dips his head down, spreading her apart and burying his lips between her own.

The sharp, tangy smell and salty taste used to overwhelm Armin, but now it serves to arouse him. A woman's scent. Mikasa's scent. He licks her clit starting all the way from the back of his tongue, and enjoys the way he can feel her heart pound all the way down here.

Mikasa isn't a very dramatic lover, although she has tells. He listens closely for changes in her breathing. Sharp intakes, stops or stutters mean he's doing the right thing-- no human could help themselves. But she has the enviable ability to remain relaxed even while being stimulated. Eren holds her breasts and teases her nipples, nuzzling behind her neck, and she crosses her arms over his own.

Her build is slow, but when it becomes too much to bear, she tosses her head to bury in the crook of Eren's neck and raises her hips to grind harder into Armin's mouth. He sucks enthusiastically at her clit and with a free hand pushes two fingers inside her, just enough to provide the sensation that something was "there".

After a little more attention and some encouraging pressure from inside, Mikasa arches her back and releases a long, shuddering breath. Armin can feel that telltale pulsing around his fingers that happens when she orgasms. Her body spasms too, slow and languid, in rhythm with what he was feeling.

Armin sits back up, and licks the wetness from his lips. There's plenty of it on his hand now too. He rubs the impossibly slick feeling between his thumb and forefingers. Normally, it would be great just to slather himself in this take care of things right now. He has a raging erection from pleasing Mikasa, something he cannot help after immersing himself in all those sounds and smells, and it would be heinous to let it stand much longer.

But Eren is here. He lays Mikasa down, who murmurs something and stretches, perfectly pleased to stay there as far as Armin could tell. Eren smiles and kisses her, and she takes hold of a pillow to clutch to her chest. The only time Armin sees the remnants of the girl that still lives inside her are when Eren smiles.

When he turns his attention towards Armin, Armin feels something like a boy tighten in his heart too. Eren's eyes lack the deceit most people carry around with them, and his stare can feel exposing.

However, the thoughts behind them are usually quite simple.

"Wait a second, you've kind of got..." Eren mumbles, and leans forward to lick under Armin's lips, and below his nose, and the urge to roll his eyes is immense.

"Yes, it's very messy down there," Armin replies flatly, and Mikasa gives him a good nudge with her knee.

"But you're so good at it," Eren says close to his lips, not missing a beat. He tangles his fingers in Armin's hair and brushes it back, "it's hard just to sit back and watch."

Armin closes his eyes and enjoys it. His sentiments are always so tempting. Especially when he's fluffing Armin's hair.

"We know this won't work as some kind of free-for-all," as many clumsy attempts in the past had proven to them, "I don't mind it, this way."

He can feel Eren grin against his skin.

"I'm complimenting you too."

"Ah-- well," Armin opens his eyes in a fluster, and clears his throat, "you'll have to give me a moment. My jaw is a bit sore."

Eren gives him a ruthless noogie from either side of the head. Even Mikasa is gently laughing from behind her pillow.

"I'm not saying it to get something out of you, dork," he says, and holds Armin's face in his hands, lovingly, "you have to stop reading so hard into people."

"It's my job," Armin replies, holding one of Eren's hands, "I don't think there's a single person in the world as forthcoming as you."

"Okay then, forthcoming..." he smiles with a hint of impishness, brushing Armin's hair back and touching him behind the ear, "can I put it in today? Please?"

"I have to ride a horse tomorrow. I have to ride a horse for a _very long time._ "

"Yeah, I know," Eren chuckles, giving that he would never compromise the mission, "it was worth a shot."

They had been slowly coming closer together with each word, even the ones that were teasing, and they close the distance with a kiss. Armin is reminded of his arousal as he casually looks down to see that Eren is straining against his own undergarments as well.

"Sorry about all the chit-chat," he apologizes briefly, between kisses.

"Don't worry about it. You always talk too much."

"However, my jaw isn't quite so sore..."

"Nah, twice in a row isn't fair," Eren dismisses, and runs his hands down Armin's hips and thighs to unclothe him the rest of the way, aided by a little helpful twisting and kicking. The move leaves him with a face full of boner, "I'll do it."

Armin has to give it to him, Eren is never shy. He licks Armin from base to tip in one long stroke, coating his tongue in pre-come. It sends a slow-moving shiver up Armin's spine as his cock twitches in response to finally being touched. The thought of how long it's been since he's had someone else's attention idly passes through his mind, but he soon forgets as Eren licks him again and runs both his palms, now slick with spit, up and down either side of his shaft.

It feels so good. His hands grasp at the bare skin of Eren's shoulders for the need of something to anchor himself to, but Armin finds his fingers clumsy. Even after all of their experiences, he's sure he's still making some kind of unattractive face. He takes a deep breath that hitches halfway through.

Eren looks up at him through the corner of his eye, lapping at the head of his dick and taking it into his mouth. Armin knows what he's asking, and gives a fluttering nod.

The hot-wet feeling of being completely enveloped in his mouth is worth it. Eren can nearly take him all in at once, if he dips up and down quick enough and gains momentum.

Armin tilts his head back and lets out a creaky moan. It _has_ been a long time, even on his own. A creeping warmth fingers up his neck fast, too early for his own liking.

"Eren, please..."

He stalls, looking up at Armin again.

"...please slow down."

"Slow down?" Eren says with a line of spit still trailing from his mouth to Armin's cock, "I wasn't even going that fast."

"He doesn't want to come yet," Mikasa explains, sitting up to touch shoulders with him, and Armin remembers how deadly their combination can be, "right, Armin."

He lets his head fall against Mikasa's, and that's as good as a yes. She kisses his cheek. Eren shrugs and continues a little more gently than he started.

Mikasa's touch also serves to calm him down a little. While Eren was warm, she was always a little cool. She strokes his cheek and neck and it's refreshing, like a splash of fresh water.

He evens out his breathing. Sensations builds up slowly, instead of rushing all at once. Armin rocks his hips gently in time with Eren's sucking, gathering all the pleasure he can before squeezing Eren on the shoulder to let him know to back off if he didn't want a mouthful or a face full.

They've used the signal for long enough that he doesn't have to think about it; Eren withdraws and straightens up to engulf Armin's lips in a full-mouthed kiss as he vigorously strokes his spit-slick dick to give him release. He happily swallows Armin's moans, enjoying the feeling of them reverberating in his own throat as he comes, backing off if only to let Armin finally breathe. Mikasa holds him and he melts against her, head lolling languid against her shoulder.

Eren sits back to admire the scene. The two of them were uncommonly beautiful, soft Armin and pale Mikasa, wonderful separate but even more lovely together. These feelings of warmth came unbidden and he did not rear against them. Why would he fight what felt so natural? They were the home he returns to.

Armin blinks out of his partial stupor, sitting up to straighten out his hair and give a blushing smile of satisfaction. Mikasa sits in Eren's lap and kisses his nose. They nuzzle, and he savors the feeling of her eyelashes brushing his cheek. Armin leans in to kiss the corner of his lips, and Eren wraps his arms around the both of them. They both put an arm around his neck, and even he can feel secure.

None of them are difficult, but Eren is the least so, known to grind himself to completion on more than one occasion. Mikasa reaches into his underclothes and when he immediately bucks, Armin pushes him to lie on his back. He makes no complaint, grinning wickedly and instead making work of kissing Armin while Mikasa makes work of freeing him.

He loves the way Armin's hair frames his face as he hovers over him. He loves the way Mikasa's lips feel around his cock. Being gentle is not his strong suit, but he remembers to try and not choke anyone while he's getting blown as much as he's itching to practically leap into her throat.

Not to mention the terrible fate that would befall them if she were to bite him somehow...

But Armin pins him down well, even if Eren could toss him off easily, the effort behind it is enough to keep him still. It's not often that anything overpowers him, and the feeling pleasantly unusual. Mikasa can be trusted with the rest; her mouth silky, soft and eager.

He comes hard and without warning, biting Armin's lip. Mikasa isn't squeamish, and swallows.

They count every moment afterwards, knowing that everything must end, but for each second stubbornly refusing to yield to the curtain, to relish just another breath as one.

\---

"You sure you don't want me to help put that all back on?" Eren, a little too eager from his place still-naked in bed, switching his gaze from Armin working on the last of his shirt buttons and Mikasa slipping on her pants.

Unless you're injured, there's absolutely no reason to wear a uniform without a harness. A walk of shame may be involved here.

"It's alright," Armin assures. He carefully rolls up the belts as they were taught to, so they won't become damaged, wraps that in his jacket and tucks it all under his arm in a bundle, "the guards know what we're doing, and honestly, I'd like to go straight to bed."  
Mikasa makes a sound of agreement. They quickly re-dress as what's left of the night ticks by too fast.

Their partings are much more subdued than their reunions. Prolonged goodbyes are as painful as they are pointless when the future is as uncertain as theirs is.

"...Good luck on tomorrow's mission."

"Don't die."

All at once, they answer:

"I won't."

Armin returns to his room to find that his candle has guttered out. The moths that had died in its wax now were fossilized, and that pool a grotesque array of powdery wings sticking up this way and that.

The night has cleared somewhat, and a few stray moonbeams are reflecting in his wash basin. He washes off his hands and his face. Washes off the smell. Washes off the warmth. His bed is cold and starchy.

He wonders how Eren sleeps, surrounded by all the traces of their intercourse. He wonders if Mikasa sheds her skin like he does.

By morning, the night is all but forgotten, and his determination is renewed. He puts on his cloak.

The mission goes off relatively well. 17 soldiers die. Mikasa loses her new recruit. Eren comes back in one piece, as far as he's allowed to know.

He cleans up the mess on his desk one moth at a time. He rolls out a fresh piece of parchment.


End file.
